High speed and high power laser scribing methods and systems

ABSTRACT

A method of scribing a graphic on a material is provided, in which laser output is applied to the material. The laser output is moved relative to the material at a high speed greater than 10 m per second, and at a high power greater than 500 W, to scribe a graphic on a surface of the material. Also provided is a system for scribing a graphic on a material. The method and system of the invention are especially useful in the scribing of building materials.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of provisionalapplications 60/943,943,317 filed Jun. 12, 2007 and 60/952,431 filedJul. 27, 2007, the disclosures of which are herewith incorporated byreference in their entireties.

FIELD OF THE INVENTION

The invention generally relates to a laser-based method and system forscribing graphics on materials, especially building materials, at highprocessing rates suitable for industrial scale manufacturing.

BACKGROUND OF THE INVENTION

Residential and commercial building products include interior buildingproducts such as drywall, countertops, bathroom fixtures, kitchencabinets, interior doors, flooring, wall panels, ceiling tiles, andbuilding exterior products such as decking, siding, trim, fencing,windows and exterior doors. These products are made of gypsum, vinyl,acrylic, hardboard, tempered glass, annealed glass, resin composites,various laminates, veneer, low profile carpet tiles, fiberglass,ceramic, granite, plastic and plastic wood composites, and a variety ofother materials. There is often a desire to offer such components indecorative fashion with various graphic designs imprinted on thematerials.

Conventional printing technologies such as embossing and ink-jetprinting often produce unappealing aesthetics. Other processes such assandblasting and veneering have the drawback of high cost.

It would seem that laser engraving building products would offer anattractive means to decorate building products. However, commercialproduction lasers have not been used to decorate building products in alarge scale production at economically attractive rates. It is believedthat at least two factors explain why building products are not laseretched on a mass production scale. These factors are the relatively lowscan speeds and relatively low power capabilities of commercial laserengraving systems.

With regard to scan speeds, a laser beam can be driven with linearmotors or lead screw drives on x-y tables at typical laser scan speedsof typically 0.5 to 3.0 meters per second. This method is common in thelaser cutting industry which uses 1,000-10,000 watt lasers to cut steel,for example. Companies such as Amada®, Trumph, Rofin®, Fanuc®, andPanasonic® provide such 1,000-10,000 watt laser systems.

The speeds of these conventional linear-motor-driven laser systems wouldtake several total processing minutes just to etch a square foot ofmaterial. For example, a recent advertisement of a leading laser system,Vyteck L-Star, purports that it is the “world's fastest laser system forthe stone, tile and glass industries”. The advertisement furtherpurports that the “L-Star outperforms the competition with engravingspeeds up to 150 ips” or 3.8 meters per second.

The inventors recognized, however, that the speeds obtained byconventional linear-motor systems would not allow economicalscribe-processing of building products because it would take far toolong to decorate a substrate. It is estimated that a laser of thislinear-motor type would take several minutes per square foot to etchgraphic patterns on building materials. For example, at this speed, itis estimated that it could take about 6 minutes to etch a complexgraphic pattern on a square foot of medium density fiberboard, a commonsubstrate for building materials. Thus, the unit manufacturing costswould be far too high to economically process such building materials ona mass scale. The slow speed of this linear motor would likely not be apractical or economical method to laze graphic patterns on woodcomposite decking, flooring, wood composite products or any othertypical building product substrate at high volumes. It could takeseveral minutes per square foot to laze complex wood grain patterns on asquare foot of engineered wood or plastic lumber with current laserengraving technology. The inventors believe that this is why suchbuilding materials are not laser etched in high volumes.

Alternatively, galvanometer-driven mirrors (or galvo mirrors for short)can be used to control the movement of a laser beam on the surface of amaterial. The galvo mirrors are moved by a control signal, and thatmovement correspondingly causes the output beam of the laser to be movedon the material along a desired path, thereby enabling creation of apattern. This method finds wide application in the laser engraving of avariety of materials including steel, wood and plastic, using 50-250watt lasers.

Laser systems driven by galvo mirrors are employed on relatively smallscales (generally less than 61 cm (or two feet) square field size) andat low speeds (less than 5 meters per second engraving speed) with lowpower (generally between 50-250 watts). These systems typically etchproducts such as wine glasses, small brass bushings, small woodenplaques or small granite slabs. Unlike lasers driven with linear motors,galvo mirror-driven systems lack the laser power to process relativelylarge parts. As with linear-motor driven lasers, the operation of galvomirror-systems is too slow to produce building product partseconomically.

SUMMARY OF THE INVENTION

A first aspect of the invention is directed to a method of scribing agraphic on a material, in which laser output is applied to the material.The laser output is moved relative to the material at a high speedgreater than 10 meters per second, and the laser output has a high powergreater than 500 W, to scribe a graphic on a surface of the material.

A second aspect of the invention involves a system for scribing agraphic on a material. The system includes a laser operable at a highpower output greater than 500 W, and a mirror system for moving thelaser output at a speed greater than 10 meters per second to scribe agraphic on a surface of the material.

A third aspect of the invention is directed to a graphics processingmodule that efficiently processes the graphic image in order to controlpositioning of the mirrors to scribe the graphic and control the powerof the laser.

Additional aspects of the invention, including additional methods,additional systems, devices, apparatus, articles, and others, willbecome apparent upon viewing the accompanying drawings and reading thedetailed description below.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings are incorporated in and constitute a part ofthe specification. The drawings, together with the general descriptiongiven above and the detailed description of the exemplary embodiment(s)and method(s) given below, serve to explain the principles of theinvention. In such drawings:

FIG. 1 is a schematic view of a system for scribing a graphic on amaterial according to an embodiment of the invention; and

FIG. 2 is a schematic view of a system for scribing a graphic on amaterial according to another embodiment of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S) AND EXEMPLARY METHOD(S)

Reference will now be made in detail to exemplary embodiment(s) andmethod(s) of the invention as illustrated in the accompanying drawings,in which like reference characters designate like or corresponding partsthroughout the drawings. It should be noted, however, that the inventionin its broader aspects is not limited to the specific details,representative devices and methods, and illustrative examples shown anddescribed in this detailed description section.

The inventors know of no one who has suggested high speed engravingprocessing with high-power lasers prior to this invention. The inventorshave determined that lasers using high power (greater than 500 watts)and high speed (greater than 10 meters per second) would be asignificant improvement to conventional systems and a commerciallyreasonable way to laze graphics and patterns on building productsubstrates and other materials in mass production to achieve low unitcosts and thus satisfactory economics.

In particular exemplary embodiments, 2,000 watt or higher, and even2,500 watt or higher lasers coupled to ultra high speed scan headscapable of 30 meters per second or greater speeds offer attractive unitmanufacturing costs and economics. The inventors have calculated thatlaser scan speeds of 30-50 meters per second can etch graphic patternsin time frames measured in seconds per square foot and unit costsmeasured in pennies per square foot. As referred to herein, “speed” isthe speed of the laser output (e.g., beam) relative to the surface ofthe material. Relative speed may be imparted by moving the laser outputwhile maintaining the material stationary, or by moving the materialwhile maintaining the laser output stationary, or by simultaneouslymoving the laser output and material in different directions and/or atdifferent rates.

According to an exemplary embodiment, a high-speed high power laser isused to form graphics and patterns on a building material substrate. Thelaser, represented by reference numeral 32 in FIG. 1, is a high powerlaser having greater than 500 W of output power, and in certainexemplary embodiments greater than a 1000 W (1 kW), 2000 W (2 kW) oreven greater than 2500 W (2.5 kW). The laser power output referred toherein is continuous, as distinguished from the power output when alaser has a temporary energy surge, or when the laser is pulsed. Thecontinuous power can be varied by adjusting the power setting on thelaser. The laser frequency is typically in the range of, for example, 10to 60 kHz. An exemplary commercial laser is available from Rofin-SinarTechnologies, Inc. 2.5 kW CO₂ laser, model number DC025.

The output 34 of the laser 32 is coupled to a scanning head 36, whichincludes a controllable, movable relatively light weight coated mirrorthat is capable of scanning the laser output at a relatively high speed.In exemplary embodiments the speeds are greater than 10 m per second, oreven 30 m per second or higher with higher power lasers. As describedherein, scan speeds of up to 65 m per second or even higher may beemployed. Moreover, the laser output 38 can be scanned across the workpiece on working surface 40, as shown in FIG. 1. For example, the output38 may scan lengths of 0.9 m (3 feet) or more.

Laser systems according to this embodiment use very high scan speeds inorder to achieve low unit cost in processing materials, such asstructural and decorative building materials. Examples of materials thatmay be treated using the systems and methods embodied herein includeglass (tempered glass and/or annealed glass), stone, ceramic, granite,engineered wood, laminates, metal, plastic, gypsum, siding, fiberglassreinforced plastic, wood composites, vinyl, acrylic, hardboard, veneer,low profile carpet tiles, etc. Lasers that scan at such high speedsaccording to embodiments of the invention employ exceptional power toprovide high energy density per unit time for satisfactorily etchinggraphics on building materials and other substrates at industrialproduction levels. At laser powers below 500 watts, a laser operating athigh scan speed of 30-50 meters per second would simply not havesufficient power to effectively etch graphic images on buildingproducts.

In order to provide a laser system with 1,000-2,500 watts that is galvodriven at high scan speeds, e.g., ranging from 30-50 meters/second, inan exemplary embodiment of the invention lightweight high technologymirror systems with high temperature coatings as commercially availableare used. An exemplary commercially available lightweight hightechnology mirror system is ScanLab AG, Model PowerSCAN33 Be, 3-axisGalvanometer scanner with 33 mm Be Mirrors. The high temperature coatingis believed to be a physical vapor deposited alloy. The lightweightberyllium substrate is coated with materials allowing the mirror surfaceto reflect over 98% of the CO₂ wavelength, 10.6 microns. The lightweighthigh technology mirror systems allow the galvanometers (or “galvos” forshort) to move the laser output (e.g., beam) in a repeatable butefficient fashion over the substrate surface. The scan speed of such alaser system is surprisingly an order of magnitude higher than the laserscan speeds achieved with either linear drives or conventional galvomirrors. Using such a lightweight mirror system, the inventors haveachieved laser scan speeds in excess of 65 meters per second compared tomaximum scan speeds of 4-5 meters per second with conventional laserengraving technology.

The system includes a controller, designated by reference numeral 30 inFIG. 1, which is capable of keeping up with the ultra high scan speedsproduced by the lightweight mirrors and making the necessary powerchanges at the specified speed. To create fine resolution graphics, thecontroller makes those power changes at high rates, such as every fewmillimeters of beam scan. The scan speed of the laser will determine theamount of power changes within the graphic. The type (e.g., complexityand intricacy) and depth of the graphic will also influence how it isscribed on the substrate. An exemplary commercially available controlleris the Model Foresight Controller, Embedded Laser Process Controlleravailable through LasX Industries, Inc. The interdependence of powerchanges, controller speed, and laser scan speed is illustrated in TablesII and III below.

FIG. 2 illustrates another embodiment of a system for scribingmaterials, such as building materials. The system, generally designatedby reference numeral 10, includes a laser 11 for generating a laser beam12 in a direction of a computer-controlled mirror system.

The illustrated mirror system includes an x-axis mirror 13 rotatablymounted on and driven by an x-axis galvanometer 14. The x-axisgalvanometer 14 is adapted to rotate and cause the rotation of thex-axis mirror 13. Rotation of the x-axis mirror 13 while the laser beam12 is incident on the mirror 13 causes the laser beam 12 to move alongthe x-axis. A (numerical) control computer 15 controls the output of apower source 16 to control the x-axis galvanometer's 14 rotation of thex-axis mirror 13. The laser beam 12 is deflected by the x-axis mirror 13and directed toward a y-axis mirror 17 rotatably mounted on y-axisgalvanometer 18. The y-axis galvanometer 18 is adapted to rotate andcause rotation of the y-axis mirror 17. Rotation of the y-axis mirror 17causes movement of the laser beam 12 incident on mirror 17 along they-axis. The control computer 15 controls the output of the power source16 delivered to y-axis galvanometer 18 for controlling rotation of they-axis galvanometer 18.

The laser beam 12 is deflected by the y-axis mirror 17 and directedthrough a focusing lens 19 adapted to focus the laser beam 12. The lens19 may be a multi-element flat-field focusing lens assembly, whichoptically maintains the focused spot on a flat plane as the laser beam12 moves across the material to scribe a graphic. The lens 19, mirrors13, 17 and galvanometers 14, 18 can be housed in a galvanometer block(not shown).

The apparatus 10 further includes a working surface 20 which can be asolid substrate such as a table, or even a fluidized bed. A material (orwork piece) 21 is placed on the working surface 20. The material 21includes a working surface 22 to be scribed. The working surface 20 canbe adjusted vertically to adjust the distance from the lens 19 to thesurface 22 of the material 21. The laser beam 12 is directed by themirrors 13, 17 against the working surface 22 of the material 21.Usually the laser beam 12 is directed generally perpendicular to theworking surface 22, but different graphics can be achieved by adjustingthe angle between the laser beam 12 and the working surface 22 fromabout 45° to about 135°. Relative movement between the laser beam 12 incontact with the working surface 22 of the material 21 causes a graphic23 to be scribed on the surface 22. The movements and timing of themirrors 13, 17 and the power of the laser beam 12 are controlled by thenumerical control computer 15 to scribe the specific desired graphic 23.As referred to herein, relative movement may involve movement of thelaser beam 12 (e.g., using the mirror system) as the working surface 22remains stationary, movement of the working surface 22 while the laserbeam 12 remains stationary, or a combination of simultaneous movement ofthe laser beam 12 and the working surface 22 in different directionsand/or at different speeds.

A second computer such as a work station computer (not shown) can beused in the method to facilitate the formation of the desired graphic.For example, a graphic can be scanned into the work station computer,converted into the proper format, and then introduced into the controlcomputer. The numerical control computer then controls the galvanometers14, 18 and mirrors 13, 17 and the power output of the laser beam 12 toform the graphic on the surface of the material 22 at the appropriatepower and movement velocity for high throughput.

The system 10 can also include a tank 24 to inject a gas such as aninert gas into the working zone. The amount of gas can be controlled bythe numerical control computer or by other means.

The term scribe, as used herein, means to contact the material with alaser beam to form a graphic. In the course of scribing, the laser beam12 applies power to the substrate, thereby causing a visuallyperceptible change to the substrate, such as by causing removal of acoating of the substrate, removal of substrate material, etc. The resultis a transformation of the substrate that is visually perceptible. Theterm graphic refers to decorative and artistic designs, non-decorativedesigns, patterns, graphic images, looks, alpha-numeric characters,logos, other identification, etc.

Two technologies of laser scribing graphics on materials include rasterand vector technologies. Raster technology can be defined as the laserdrawing of a graphic either in the horizontal or vertical direction byscanning back and forth in a continuous manner until the graphic isfinished. Vector drawing can be defined as the laser outlining eachindividual part of the graphic until the entire graphic is complete.

The amount of laser power needed to provide an acceptable design at ahigh speed will be determined by the nature of the substrate. The laserpower may range anywhere above 500 watts, and as high as, for example,5,000 watts. For example, the power needed to laze on cotton shirts orsilk at high scan speeds might require only 500 watts, whereas it mighttake a much higher power, such as 2,500 watts or greater to efficientlylaze on plastic lumber, engineered wood or denim at similar scan speeds.This concept may also apply to smaller size substrates as well, such asfor mass customization.

According to an embodiment, control information for controlling thelaser may be stored in advance in the controller 30. The stored controlinformation may be linked to one or many different graphics, e.g.,patterns.

The inventors have obtained numerous materials and building productsincluding plastic lumber, vinyl siding, wood composites, drywall,laminate products, hardboard, wood fiber products, tempered glass,annealed glass, drywall, vinyl, ceiling tiles, flooring, fiberglass andresin components, carpet tile, and attempted to impart fashion designson these components using a high speed (greater than 10 meters persecond and preferably 30 meters per second) and high laser power(greater than 500 watts, and in certain exemplary embodiments 2,000watts or greater or as much as 2,500 watts). The experimental resultswere nothing short of surprising in that in every case the laser wasable to impart striking and artistic designs on these products in amatter of seconds. Hence, the techniques disclosed in the embodimentsprovide, for the first time, an economic breakthrough for laser etchinggraphic images on building products.

The inventors were surprised with the attractive and intricate graphicdesigns and textures that could be scribed at high speeds on acrylic,vinyl and fiberglass building product components, plastic lumber, andwood composites. A variety of graphics and wood grain patterns werescribed on these building products in time frames measured in secondsper square foot. Plain “vanilla”-decor products were turned intodecorative components in seconds. Oak, walnut, cedar and mahogany woodgrain patterns were lazed on plastic lumber and wood composites toprovide a real wood-simulated deck component. Even exotic wood grainpatterns such as leopard wood grain patterns and other floral andgraphic patterns were lazed on plastic lumber and wood composites athigh throughput rates to give striking new designs. Most importantly,such designs were created in such short time frames, that the laseretching process would indeed be economical for large scale production.Graphics lazed on drywall added a new degree of freedom to the designaesthetics of interior walls and represented yet another surprise.Lazing different textures on flooring products ranging from hard andsoft boards to ceramic tile provided new low cost alternatives to adddecoration and design to flooring. Etched graphics and patterns can evenbe lazed on mirrors to provide a totally new mass-produced aestheticallypleasing appearance.

The inventors believe that the laser system embodied herein can providealmost limitless fashion and design features to building products forthe first time in an economical production process. The inventors havedemonstrated that 2,500 watt lasers driven by galvometric mirrors canindeed decorate building products in seconds and thus are veryeconomical if not revolutionary to the cost structure. To furtherimprove the economics, the products can be laser-scribed at high speeds(e.g., greater than 10 meters per second) and high powers (e.g., greaterthan 500 watts) while coupled to a simple moving conveyor system. Thelaser system can “print-on-the-fly” in a continuous laser scribingprocess. Also, there are several other means to improve the economics,such as: multiple lasers can be put in place along a production line todouble or triple throughput; the scan head can be attached to a linearmotor that will laser etch a larger material in sections until theentire piece is finished; and the distance from the laser to the workingsurface can be increased to allow laser etching larger pieces ormultiple pieces at once.

For example, laser etching plastic lumber in a continuous process formass production may involve one 2,500 watt laser directed at a workingsurface of 50.8 cm (20 inches) that operates at high speeds to match theline speed of the process. But to properly laser etch interior doors formass production that are some 3 foot by 8 foot in size, it may be moreefficient to employ multiple lasers or a linear motor to cover theentire working surface. Regardless of the setup, the inventors havedetermined that laser powers of 500 or higher (e.g., 500-2,500 watts)and laser scan speeds of 10 meters per second on higher (e.g., from10-50 meters per second) produce satisfactory economics in unit costsfor lazing graphics on building products. The actual unit costs could bereduced from dollars per square foot to cents per square foot byincreasing the laser speed from the industry standard 3.8 meters persecond to, for example, 50 meters per second.

The power and speeds should be controlled to avoid any undesirablyconsequences of over-treatment, such as complete carbonization,burn-through and/or melting of the scribed material.

It should be understood that the methods and systems described hereinmay be used for scribing materials other than building materials. Othersmaterials that may be scribed in accordance with embodiments describedherein include denim fabric and leather, such as found in the garmentindustry.

Computer hardware and software for carrying out the embodiments of theinvention described herein may be any kind, e.g., either generalpurpose, or some specific purpose such as a workstation. The computermay be a Pentium® class computer, running Windows XP®, Windows Vista®,or Linux®, or may be a Macintosh® computer. The computer may also be ahandheld computer, such as a FDA, cellphone, or laptop.

The programs may be written in C, or Java, Brew or any other programminglanguage. The programs may be resident on a storage medium, e.g.,magnetic or optical, of, e.g., the computer hard drive, a removable diskor media such as a memory stick or SD media, or other removable medium.The programs may also be run over a network, for example, with a serveror other machine sending signals to one or more local machines, whichallows the local machine(s) to carry out the operations describedherein.

Examples

To demonstrate the influence of substrate material and graphic imagepattern on laser power and scan speed, the experiments set forth inTable I below were carried out on various substrates.

TABLE I Graphic Laser Power Laser Scan Substrate Image (Watts) Speed(m/s) PVC Composite Cedar 1750 10 Polethylene wood Cedar 2500 10composite Polyethylene wood Maple 2000 10 composite Polyethylene woodLeopard 1750 10 composite Hardboard Walnut 2500 15 Painted MDF (2 paintSimple Oak 2500 40 layers) Medium Density Rose 2500 15 Fiberboard (MDF)Pedals Medium Density Simple 1500 22 Fiberboard (MDF) Walnut MediumDensity Oak Cross 1500 22 Fiberboard (MDF) Grain Painted Hardboard (2Maple 1375 15 paint layers) Painted Hardboard (1 Simple Oak 2500 28paint layer) Primed Hardboard Simple Oak 2500 32 PVC Cedar 2500 10Reaction-Injected Cedar 2250 10 Molded Plastics

The effects of controller speed on laser power change width for twoseparate graphic images are demonstrated by Tables II and III below.Table II contains data for 32 laser lines per inch and Table IIIcontains data for 60 laser lines per inch. For example, a graphic imagewith 32 lines per inch requiring the laser power to change every 2pixels can achieve a maximum laser span speed of 15 m/s at a controllerspeed of 10,000 pixels per second (see Table II). In order to double thelaser speed to 30 m/s in this instance, the controller should have aprocessing power of 20,000 pixels per second. As the laser lines perinch increase (comparing Table II to Table III), the controller speedbecomes more important for maintaining high laser line speed.

TABLE II Specific Graphic at 32 lines/inch Power Change Width ControllerSpeed Laser Scan Speed (Pixels) (Pixels/second) (m/s) 4 10,000 31 420,000 62 3 10,000 23 3 20,000 46 2 10,000 15 2 20,000 30 1 10,000 7 120,000 14 1 40,000 28 1 50,000 35

TABLE III Specific Graphic at 60 lines/inch Power Change WidthController Speed Laser Scan Speed (Pixels) (Pixels/second) (m/s) 410,000 16 4 20,000 32 3 10,000 12 3 20,000 24 2 10,000 8 2 20,000 16 110,000 4 1 20,000 8 1 40,000 16 1 50,000 20

The foregoing detailed description of the certain exemplary embodimentsof the invention has been provided for the purpose of explaining theprinciples of the invention and its practical application, therebyenabling others skilled in the art to understand the invention forvarious embodiments and with various modifications as are suited to theparticular use contemplated. This description is not intended to beexhaustive or to limit the invention to the precise embodimentsdisclosed. Although only a few embodiments have been disclosed in detailabove, other embodiments are possible and the inventors intend these tobe encompassed within this specification and the scope of the appendedclaims. The specification describes specific examples to accomplish amore general goal that may be accomplished in another way. Modificationsand equivalents will be apparent to practitioners skilled in this artand are encompassed within the spirit and scope of the appended claimsand their appropriate equivalents. This disclosure is intended to beexemplary, and the claims are intended to cover any modification oralternative which might be predictable to a person having ordinary skillin the art. For example, other kinds and wattages of lasers, beyondthose described above, could be used with this technique.

Only those claims which use the words “means for” are to be interpretedunder 35 USC 112, sixth paragraph. Moreover, no limitations from thespecification are to be read into any claims, unless those limitationsare expressly included in the claims.

1-23. (canceled)
 24. A system for scribing a graphic on a material,comprising: a laser operable at a high power output greater than 500 W;and a mirror system for moving output of the laser at a speed greaterthan 10 m per second to scribe a graphic on a surface of the material.25. A system as in claim 24, further comprising a controller for storinginformation indicative of the graphics to set control information forthe laser.
 26. A system as in claim 24, wherein the material comprises aproduct that is used in or for commercial or residential buildinginterior or exterior components.
 27. A system as in claim 26, whereinthe building material comprises at least one of an exterior deckingmaterial, exterior playground material, or a home exterior material. 28.A system as in claim 26, wherein the building material comprises acomposite building material made from multiple different materials. 29.A system as in claim 24, wherein said material comprises at least one offiberglass reinforced plastic, coated steel, or wood composite board.30. A system as in claim 24, wherein the material comprises a glassproduct.
 31. A system as in claim 30, wherein the material comprises awindow.
 32. A system as in claim 30, wherein the material comprises amirror.
 33. A system as in claim 26, wherein the material comprises aflooring product.
 34. A system as in claim 26, wherein the materialcomprises a ceiling tile product.
 35. A system as in claim 26 whereinthe material comprises a drywall product.
 36. A system as in claim 24,wherein the material comprises a clear plastic material.
 37. A system asin claim 24, wherein the mirror system comprises a beryllium substratewhich is coated.
 38. A system as in claim 24, wherein the power outputof the laser is greater than 1000 W, and the mirror system is capable ofmoving the laser output at a speed greater than 20 m per second.
 39. Asystem as in claim 24, wherein the power output of the laser is greaterthan 2000 W, and the mirror system is capable of moving the laser outputat a speed greater than 30 m per second.
 40. A system as in claim 24,further comprising a controller for changing the speed of movement ofthe laser.
 41. A system as in claim 24, further comprising a controllerfor changing the power output of the laser.